The overall goal of this project is to implement an inquiry-based approach to improve parent and teacher practices, which will support and improve developmental outcomes for infants and toddlers. The intervention will have two phases. Phase 1 will focus on supporting Responsive Caregiving practices (for both parents and teachers) to promote the social and emotional development of infants and toddlers. Phase 2 will focus on the Facilitation of Discovery and Exploration (again, for both parents and teachers), to promote cognitive as well as language and early literacy outcomes of infants and toddlers. A randomized control trial (RCT) will be implemented to evaluate the efficacy of the Phase 1 and Phase 2 components. The intervention approach is based on Practice-Based Coaching (P-BS), the coaching model already in use in Head Start/Early Head Start. We will enhance the current coaching model (P-BS) as well as current teaching and learning practices, by integrating an intentional focus on inquiry.